Currently several different types are known of mechanisms in general, and of lever mechanisms in particular, i.e. several types of mechanisms, constituted by an assembly of mechanical elements, which are adapted to transmit motion in a complex machine, in which certain elements describe particular curves and can convert motion of one type to motion of another type.
Such mechanisms are nowadays used in uncountable machines and mechanical devices: a typical example of a mechanism is the crankshaft mechanism, which can convert alternating linear motion to circular motion.
Conventional lever mechanisms are not devoid of drawbacks, among which is the fact that some of the mechanical elements that constitute them are subject to high wear from sliding, which derives from the friction that arises between the surfaces of such mechanical elements during operation and the movement of the kinematic mechanism.
Another drawback of such conventional lever mechanisms consists in that they do not allow an adequate and lasting lubrication of the mechanical elements that comprise them, consequently making it necessary to carry out frequent maintenance operations.
A further drawback of such conventional lever mechanisms consists in that the resistance to movement, which is produced by the friction between the surfaces of the mechanical elements that comprise them, makes a greater force necessary in order to perform such movement.